3 ½ pounds bone-in chicken pieces (or use a 31/2 pound chicken cut into 8 pieces)
2 tsp. kosher salt
1 tsp. black pepper
1 T. extra-virgin olive oil
5 oz. pancetta, diced
3 garlic cloves, thinly sliced
2 anchovy fillets
¼ tsp. red pepper flakes
1 (28-ounce) can whole plum tomatoes
1 large basil sprig, plus more chopped basil for serving
8 oz. bocconcini, halved (or use mozzarella cut into 3/4-inch pieces)

Heat oven to 400 degrees. Pat chicken dry and season with salt and pepper. In a large oven-proof skillet, warm oil over medium-high heat. Add pancetta and cook, stirring frequently, until browned. Use a slotted spoon to transfer pancetta to a paper-towel-lined plate. Add chicken to skillet. Sear, turning only occasionally, until well browned on all sides, about 10 minutes. Transfer to a large plate. Pour off all but 1 T. oil. Add garlic, anchovy and red pepper flakes to skillet; fry 1 minute. Stir in tomatoes and basil. Cook, breaking up tomatoes with a spatula, until sauce thickens somewhat, about 10 minutes. Return chicken to skillet. Transfer skillet to oven and cook, uncovered, until chicken is no longer pink, about 30 minutes. Scatter bocconcini or mozzarella pieces over skillet. Adjust oven temperature to broil. Return skillet to oven and broil until cheese is melted and bubbling, 2 to 3 minutes (watch carefully to see that it does not burn). Garnish with pancetta and chopped basil before serving.